Unit 12
Force
Force s an important vector in mechanical engineering. Engineers must have a strong understanding of a force's direction and magnitude. Then, they must be able to calculate the effect of cumulative forces on an object. This is known as the resultant A moment measures a force's ability to spin or rotate something. If the resultant and the moment are both zero, the object is in equilibrium.
Some force calculations depend on just one fixed point within an object. These objects are known as particles. Other calculations on additional information. Sometimes an objects physical dimensions are important when examining forces. These objects are known as rigid bodies. A good tool for solving problems based on forces is a free-body diagram. They include all the forces acting on an object. Engineers provide a coordinate system with these diagrams. This ensures that other engineers understand the conventions of particular diagrams.
1.Read the textbook excerpt. Then, mark the following statements as true(T)or false(F).
1.Equilibrium depends on the moment and resultant.
2.A particle's dimensions are used in force calculations.
3.A coordinate system is part of a free-body diagram.
2.Read the sentence pairs. Choose the sentence that uses the underlined part correctly.
1. A. The cumulative effects include the results of several forces.
B.A moment describes the size of a force.
2. A.A vector indicates how likely an object is to rotate.
B. If all forces and moments are zero, an object is in equilibrium.
3. A. A particle describes all the forces on an object added together.
B.A coordinate system is a guide for reading a free-body diagram.
4. A. An object is called a rigid body when its physical properties are important.
B.A quantity that changes based on size and direction is a resultant.
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